"Hollow's" instrumentation is sparse — a rhythmic organ-like pulse and Björk's echoing voice. The blending of the electronic manipulation of the vocals, which makes it sound like there's a whole tribe of Björks singing in unison, and the thudding electronic notes give the song a feel that is primal yet futuristic." reads the commentary from NPR Music.

"it was created by drew berry for the biophilia hollow app, where you can also play with dna time signatures !" reads the announcement from the Bjork web site.